Add Command unit tests

ramen/src/command.rs

@@ -35,6 +35,16 @@ impl Command for CreateNode {
     }
 }
 
+impl From<Node> for CreateNode {
+    fn from(node: Node) -> Self {
+        Self {
+            kind: node.kind,
+            pos: node.pos,
+            inputs: node.inputs,
+        }
+    }
+}
+
 #[derive(Clone, Debug)]
 pub struct DeleteNode {
     pub target: usize,
@@ -119,10 +129,10 @@ impl Command for SetEdge {
 
         let input = target
             .inputs
-            .get_mut(self.edge.input.slot)
+            .get_mut(self.edge.output.slot)
             .ok_or(GraphError::InvalidReference)?;
 
-        *input = Some(self.edge.output);
+        *input = Some(self.edge.input);
 
         Ok(())
     }
@@ -169,3 +179,67 @@ impl Command for DeleteEdge {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::node::AtomOp;
+
+    #[test]
+    fn create_node() -> GraphResult<()> {
+        let mut graph = Graph::new();
+
+        let cmd = CreateNode {
+            kind: NodeKind::Lit(0.0),
+            pos: glam::Vec2::ZERO,
+            inputs: vec![],
+        };
+
+        let undo = cmd.undo(&graph)?;
+
+        cmd.apply(&mut graph)?;
+        assert_eq!(graph.nodes.len(), 1);
+
+        undo.apply(&mut graph)?;
+        assert_eq!(graph.nodes.len(), 0);
+
+        Ok(())
+    }
+
+    #[test]
+    fn set_edge() -> GraphResult<()> {
+        let mut graph = Graph::new();
+
+        CreateNode::from(Node::literal(1.0)).apply(&mut graph)?;
+        CreateNode::from(Node::literal(2.0)).apply(&mut graph)?;
+
+        CreateNode::from(Node {
+            kind: NodeKind::Op(AtomOp::Add),
+            pos: glam::Vec2::ZERO,
+            inputs: vec![None; 2],
+        })
+        .apply(&mut graph)?;
+
+        SetEdge {
+            edge: Edge {
+                input: SlotIndex { node: 0, slot: 0 },
+                output: SlotIndex { node: 2, slot: 0 },
+            },
+        }
+        .apply(&mut graph)?;
+
+        SetEdge {
+            edge: Edge {
+                input: SlotIndex { node: 1, slot: 0 },
+                output: SlotIndex { node: 2, slot: 1 },
+            },
+        }
+        .apply(&mut graph)?;
+        
+        println!("{:#?}", graph);
+
+        graph.topological_order()?;
+
+        Ok(())
+    }
+}